code: def standardise_node(self):
      if self.word in self.WORD_TO_WORD_MAPPING:
          self.word = self.WORD_TO_WORD_MAPPING[self.word]
  
imports: import logging
  import os
  import pickle
  from collections import Counter
  import numpy
  import torch
  from torch.utils import data
label_desc: Use image node_id 4 for calling the PTBTree obj's underlying member method code with example usage: obj.standardise_node() without return types